WO2005111913A1

WO2005111913A1 - Reading device for reading out computer-generated lithograms

Info

Publication number: WO2005111913A1
Application number: PCT/EP2005/004859
Authority: WO
Inventors: Christoph Dietrich; Kay Schulte-Wieking; Robert Thomann; Steffen Scheibenstock
Original assignee: Tesa Scribos Gmbh
Priority date: 2004-05-10
Filing date: 2005-05-04
Publication date: 2005-11-24
Also published as: DE202004007636U1; DE502005011031D1; US20050247788A1; US7475820B2; EP1745407B1; US8167206B2; EP1745407A1; US20090134224A1

Abstract

The invention relates to a reading device for reading out computer-generated lithograms that are written in a storage medium. Said reading device comprises a light source for generating a light beam, recording means for detecting the image data generated by illuminating the lithogram, and means for displaying the display data generated from the image data. The aim of the invention is to create a handy reading device that provides improved variability for reading out the data contained in the dot distribution of a computer-generated lithogram. Said aim is achieved by combining all components in a portable handheld unit.

Description

Reading device for reading computer-generated lithographs

The present invention relates to a reading device for reading computer-generated lithograms.

Computer-generated lithograms are two-dimensional dot matrices, preferably with very small dimensions, which consist of individual dots with different optical properties. The lithograms are preferably in the form of holograms, but the lithograms can also be used to generate directly readable, ie without diffraction of the incident light, microtexts or microimages.

Images and / or data can be reproduced by illuminating a computer-generated hologram, for example with a coherent electromagnetic wave, in particular light wave by diffraction in transmission or reflection. The different optical properties of the individual points can be reflection properties, for example due to surface topography, varying optical path lengths in the material of the storage medium (refractive indices) or color values of the material.

The optical properties of the individual points are calculated by a computer, so that they are so-called computer-generated holograms (CGH) or generally computer-generated lithograms. With the help of the focused writing beam, the individual points of the lithogram are written into the material during writing, the focus being in the area of the surface or in the material of the storage medium. A Focusing causes a small area of action on the material of the storage medium in the area of the focus, so that a large number of points of the lithogram can be written in a small area.

Scanning an intensity-modulated write beam thus creates an area with an irregular point distribution, the computer-generated lithogram. This can be used to mark, identify and individualize any object.

A resolution of approximately 25,000 dpi is preferred when producing lithographs. In addition, only comparatively small areas are described in computer-generated lithography. These are, for example, 1 to 5 mm ^{2 in} size, although other sizes are also possible. In a lithograph for the production of digital holograms, for example, the accuracy of the writing grid must be 1000 x 1000 dots, for example, on an area of 1 × 1 mm ²

+ 0.1 μm in both orthogonal directions. In addition, the writing speed should be about 1 Mpixel / s, so that one lithogram can be written in a time of approx. Is or less.

The computer-generated lithograms explained above can carry different information. On the one hand, the computer-generated lithogram can carry holographic information which, when read out, that is to say during reproduction, reproduces directly readable information (writing, images, graphics). Likewise, the information read out can be encrypted, in particular digitized. Then the reproduced hologram contains, for example, a digital matrix similar to a one or two-dimensional barcode. Finally, the point distribution of the computer-generated lithogram per se can have directly readable information with very small dimensions, for example micro-writing. or a micro-image. In order to recognize it, an enlargement of the directly readable micro-writing is necessary, that is, a different process from reading the digital hologram. The micro-writing and / or the micro-mapping itself can in turn be encrypted. For example, a micro-image itself can represent digital information of a one- or two-dimensional bar code. Of course, a lithogram can contain both holographic information and directly readable information, that is to say a combination of all the possibilities presented.

Simple handheld readers are known from the prior art for reading out computer-generated holograms. These generally use a light beam to generate the reproduced hologram on a screen.

In addition, non-portable, permanently installed readers are known which display the information read out on a computer screen.

The technique of using computer-generated lithograms has meanwhile led to various applications in which individual products are provided with small labels, on each of which a hologram is inscribed. The lithograms used can be individualized and / or encoded in several stages, any combination of microwritings and microimages, directly readable holographic information and in turn encoded in the hologram, for example. digitized information can be combined. So far, it has not been possible to check the various information with a reading device, in particular not with a hand-held reading device.

The present invention is based on the technical problem of specifying a handy reading device which has great variability in reading out the information contained in the point distribution of a computer-generated lithogram.

The technical problem indicated above is solved according to the invention by a reading device with the features of claim 1. Further preferred configurations of the reading device are specified in the subclaims.

According to the invention, the reading device for reading out computer-generated lithograms, which are written into a storage medium, with a light source for generating a light beam, with recording means for detecting the image data generated by the light beam by illuminating the lithogram and with display means for displaying the display data generated from the image data provided, all components are combined in a portable handheld unit.

The term handheld unit is derived from the field of application of portable computers, which are also referred to as handheld computers or as personal digital assistants (PDAs). Here, too, all computer functions are arranged in a small, handy housing so that a computer that can be used on the move and is not tied to a fixed location is created. The same principle is used in the present invention for the Handheld reader used for reading computer-generated lithograms. All of the above-mentioned basic components - as well as all the other components described below - are combined in a handy unit, that is to say a handheld unit. The reader is therefore also referred to below as a handheld reader.

The hand-held reader is suitable for directing the light beam, which can be designed in particular as a laser beam, onto the computer-generated lithogram and for recording the reproduced hologram produced by diffraction effects and / or the directly readable micro image. The hand-held reader is brought up to the object carrying the lithogram, for example to the packaging of a product, in such a way that the light beam hits the lithogram.

It is also possible to provide a holder for objects with a defined shape, into which the object with the storage medium or the storage medium itself is inserted and positioned. The holder is therefore particularly suitable for bank cards or the like.

The recording means are preferably designed electronically, in particular as a conventional CCD chip or as a CMOS chip. This enables inexpensive use of standard technology for the handheld reader.

In a first preferred embodiment of the present invention, the recording means are connected directly to the display means and the display means represent the image data as display data. This makes it easy to check the reproduced hologram enables to identify directly readable information contained therein.

For example, conventional displays for mobile telephones can be used as advantageous display means. This measure can also create an inexpensive solution.

In a further preferred embodiment of the present invention, evaluation means are provided for evaluating the image data and for generating the display data. The image data generated by the recording means can thus be subjected to an analysis.

The evaluation means and the display means are preferably designed as portable handheld computers. As a result, standard technology can also be used for an inexpensive design of the handheld reader.

The analysis of the image data can be carried out in such a way that one or more areas of the image data are selected and displayed separately in succession or in parallel as display data on the display means. As a result, the image data can be enlarged and / or displayed in a special selection. Likewise, the entire image data can be displayed as display data.

A further analysis of the image data consists in deriving the display data at least partially from the image data. This can be used if the reproduced hologram contains data in coded form. It is known, for example, to include one-dimensional or two-dimensional bar codes in a computer-generated hologram deposit. These barcodes can then be recognized in the reproduced hologram as dark and light areas. The information contained in the barcode can then only be determined by a further analysis. After the analysis, this information can then be shown on the display means as readable text.

In order to be able to switch between the representation of the reproduced hologram and the data determined from it, switching means are preferably provided for setting the type of image data. Likewise, a setting can be selected in which the various information (micro image, hologram, derived information) are simultaneously displayed on the display means.

Storage means can also be provided for storing a plurality of recorded image data. This means that a number of computer-generated holograms can be analyzed without having to transfer or back up data in between. It is particularly sufficient if only the directly readable information or information which is derived from a coded form is stored in binary form.

Another embodiment of the present invention relates to a magnifying lens as an adjusting means. The magnifying lens serves for a better hands-free adjustment of the reading device relative to the position of the lithogram. The user of the reading device can directly observe the position of the light beam on the storage medium or on the object in an enlarged representation through the magnifying lens. If the spot of light precisely captures the area occupied by the lithogram, the user can trigger it Activate to capture the image data from the recording media.

The magnifying lens can be arranged outside or inside the beam path of the light beam. Depending on the arrangement, the light beam is influenced by the magnifying lens. Therefore, it is required in the arrangement of the magnifying lens in the beam path, the light beam diverges to the ^'magnifying lens to be addressed, thus largely represents a parallel beam behind the zoom lens of the light beam and is not focused on the observation plane.

Finding the small lithogram is only possible with the laser beam under certain conditions only under difficult conditions. It is therefore preferred to provide a further light source, in particular an LED producing white light, which illuminates the search area and facilitates recognition of the position of the small lithogram.

It is also possible for the evaluation means to analyze the image data recorded continuously by the recording means and to hold the image data in a suitable position of the reproduced hologram on the recording means. This analysis can be carried out on the basis of predetermined information units, for example a recognition pattern, within the reproduced hologram. If the information units can be recognized by the evaluation means at predetermined positions relative to the image plane of the recording means, the image data are recorded. An acoustic and / or optical signal generator is provided to signal the user that the image data is being recorded. If the signal transmitter is activated, the user recognizes that the hologram to be read out by him has been recognized and possibly saved.

Instead of or in addition to the eye of the user, further recording means can be provided for recording the light reflected by the storage medium. Thus, the point distribution of the computer-generated lithogram per se, that is, not the reproduced hologram, is recorded in order, for example, to be able to record a miniaturized image or micro-writing and display it on the display means. The user can then check the position of the light beam on the object or on the storage medium on the display means on the display means and thus adjust the hand-held reader.

It is therefore possible in a hand-held reader to display the point distribution with any micro-writing or micro-images that may be present. This also applies on its own, i.e. without the handheld reader also having to be able to process a reproduced hologram.

However, it is preferred that the hand-held reading device can also display the reproduced hologram with the information contained therein and / or the information derived from the reproduced hologram on the display means in addition to recognizing the micro-writing or the micro-image. The various security features of the lithogram written on the storage medium can thus be displayed optionally. In a further preferred embodiment of the present invention, at least the light source and the recording means are arranged in an optical block, while at least the evaluation means and the display means are arranged in an evaluation block. The optical block and the evaluation block are connected to one another via an electronic and / or optical interface and / or a radio interface, so that the image data generated by the recording means can be transmitted to the evaluation means. This structure creates a modular structure so that changes to one of the two different function blocks can be reacted to flexibly by exchanging one of the two blocks.

In order to form a handheld unit despite the modularity of the two blocks described, the optical block and the evaluation block are arranged on a common holder. This holder can also be part of one of the two blocks, for example the optical block, into which the other block, for example the evaluation block, can be placed.

The modular structure benefits in particular from the fact that the evaluation block is designed as a handheld computer (PDA) as standard. Since the technical development in this area is very fast and the product cycles are very short, a current, newer model of a handheld computer can be used as a replacement for a damaged evaluation block. The interfaces are therefore also preferably standardized in order to ensure that the two blocks are interchangeable. The invention is explained in more detail below with the aid of exemplary embodiments, reference being made to the attached drawing. Show in the drawing

1 shows an embodiment of a hand-held reader according to the invention in a perspective view,

2 shows a first exemplary embodiment of the construction of the components of the hand-held reader in a schematic illustration,

3 shows a second exemplary embodiment of the construction of the components of the hand-held reader in a schematic illustration,

4 shows a third exemplary embodiment of the construction of the components of the hand-held reader in a schematic illustration,

5 shows a fourth exemplary embodiment of the construction of the components of the hand-held reader in a schematic illustration,

Fig. Βa-c representations of the handheld reader with different pictorial contents of the display means and

Fig. 7 shows an embodiment of a hand-held reader according to the invention with a modular structure in a perspective view.

1 shows, for a first exemplary embodiment of a hand-held reading device 2 according to the invention, the internal structure thereof is first explained in more detail with the aid of various embodiments before the features which are visible from the outside are discussed per se.

FIG. 2 shows a schematic diagram of a first exemplary embodiment of a construction of the components of the hand-held reading device, with which the information contained in the point distribution of a computer-generated lithogram written on a storage medium 4 can be recorded.

As basic components, the structure has a light source 6 for generating a light or laser beam 8, recording means 10 for detecting the image data of the hologram (beam path 12) reproduced by the light beam 8 from the point distribution of the lithogram, and display means 14 for displaying the display data generated from the image data on. The recording means 10 are connected to the display means 14 via a data line 16. In the construction shown in FIG. 2, a beam splitter 11 and an imaging lens 13 are additionally provided in order to couple the light of the reproduced hologram out of the beam path of the light beam 8 and to achieve a suitable imaging of the reproduced hologram on the image plane of the recording means 10.

All components 6, 10 and 14 (and also further components of the reading device described below) are combined in a portable handheld unit. This can be seen in particular in FIG. 1 on the housing 18 of the handheld unit. The housing 18 has, inter alia, the display means 14 which is visible from the outside, for example as a flat screen, in particular as a display of a mobile telephone or as a screen Handheld computer (PDA) is trained. The housing 18 has an ergonomic outer shape and can easily be held in one hand by a user.

The recording means 10 shown in FIG. 2 are designed electronically, for example as a conventional CMOS or CCD chip. Therefore, a conventional and therefore inexpensive standard technology is used here.

In the exemplary embodiment shown in FIG. 2, the recording means 10 are connected directly to the display means 14 and the display means 14 directly represent the image data as display data. This is shown in FIG. 6a. The display means 14 show the image data in the manner in which they have been generated by the recording means 10. The hologram reproduced from the storage medium 4 can be seen with a black / white pattern of individual areas of a two-dimensional bar code in the upper section of the hologram and one

Character combination consisting of letters and numbers at the bottom of the hologram.

FIG. 3 shows a second exemplary embodiment of a hand-held reading device 2 according to the invention, in which the same reference numerals denote the same components as have been explained above with reference to the first exemplary embodiment.

In addition to the construction already described, evaluation means 20, which are connected to the recording means 10 and the display means 14 via data lines 16, are provided in the second exemplary embodiment. With the evaluation means 20, the image data are evaluated and the Display data generated. The evaluation means 20 are electronic and consist of at least one microprocessor, storage means and input and output interfaces. The storage means serve in particular to store a plurality of recorded image data or evaluation data. Here too, conventional and therefore inexpensive technology can be used, for example a handheld computer (PDA) can be used as display means 14 and as evaluation means 20.

With the aid of the evaluation means 20, it is possible to prepare the image data before displaying it. On the one hand, the display data can comprise at least part of the image data, preferably the entire image data. On the other hand, the display data can represent at least part of the data derived from the image data. In other words, the display data can be one or more parts of the image data recorded by the recording means 10. On the other hand, the display data can contain the information that is generated by evaluating the information contained in the reproduced hologram. For this purpose, reference is again made to an image of a one- or two-dimensional bar code, the information of which can only be obtained after an evaluation of the bar code pattern.

The two different information contents of the information shown on the display means 14 are shown in FIGS. 6a and 6b. 6a - as already described - shows the image data of the reproduced hologram recorded by the recording means 10, in the handheld reader according to FIG. 6b that from the two-dimensional barcode of the reproduced hologram information is shown legibly in writing. In the present case, it is an example of production data for a commercially available product that has been provided with a forgery-proof hologram label during production. This allows the originality of the product to be checked. The character string in the reproduced hologram according to FIG. 6a also serves this purpose. From this character string too - if necessary only in combination with the derived data according to FIG. 6b - the originality of the product can be concluded.

1 that switching means 22 in the form of a trigger are provided for setting the type of image data. The user can thus switch between the display modes shown in FIG. 6. It is also possible to combine different display modes with one another, ie to combine at least two of the display contents shown in FIG. 6 with one another.

As shown in FIGS. 2 and 3, the hand-held reader 2 has a magnifying lens 24 as an adjusting means. The magnifying lens 24 enables a user (indicated by the eye) to directly observe the region of the storage medium 4 or the object on which the storage medium 4 is arranged, which area is illuminated by the light beam 8. Since the area occupied by the computer-generated lithogram can have a dimension of 1 mm ² or less, it is not very easy to hit the lithogram without an enlargement.

For this purpose, a further light source can be provided - not shown in the figures - which illuminates the area of the lithogram, in particular with white light. This improves the recognizability of the lithogram. The light source can be designed as an LED. In addition, a target or crosshair can also be illuminated, the reflected image of which can be captured by the viewer or by the further recording means explained below.

The magnifying lens 24 is arranged in FIG. 2 outside the beam path of the light beam 8, so that the light beam 8 is not influenced by the lens 24. This configuration can also be seen in FIG. 1. The magnifying lens 24 through which the user can observe the storage medium can be seen in the upper right corner of the front of the hand-held reading device 2.

3, the magnifying lens 24 is arranged within the beam path 8. The result of this structure is that the light beam 8 is generated by the light source 6 with a slight divergence, which is canceled when passing through the magnifying lens 24.

A further aid in adjusting the handheld reader relative to the storage medium 4 is that the evaluation means 20 according to FIG. 3 analyze the image data continuously recorded by the recording means 10 and hold the image data in a suitable position of the reproduced hologram on the recording means 10. The adjustment process is therefore supported by the evaluation means, so that the adjustment carried out by hand can run faster and more reliably.

Furthermore, an acoustic and / or optical signal transmitter can be provided, which is activated when the evaluation means 20 have determined the optimal adjustment. The user is immediately informed when the reproduction of a hologram has been successfully started.

FIG. 4 shows a third exemplary embodiment of a hand-held reading device according to the invention, the same reference numerals identifying the same components as have been explained above with reference to the first two exemplary embodiments. The structure of the third embodiment corresponds essentially to the structure of the first embodiment.

In the third exemplary embodiment, recording means 26 are provided for recording the light reflected by the storage medium 4. The recording means 26 thus take the place of the eye of the user of the hand-held reader 2. The recording means 26 are connected to the display means 14 via a data line 28, so that the real image of the storage medium 4 can be directly displayed and observed by the user.

When designing the optics, it must then be taken into account that the magnifying lens 24 'has a different focal length than the magnifying lens 24 in FIG. 2, so that the imaging of the area of the lithogram on the recording means is improved, that is to say enlarged.

This technical success can also be achieved by an additional lens which can be swiveled into the beam path, on the one hand to present the user with a larger area for searching the lithogram and on the other hand to offer a larger magnification for recognizing the micro-writing or the micro-image. 5 shows a fourth exemplary embodiment of a hand-held reading device according to the invention, the same reference numerals identifying the same components as have been explained above with reference to the first three exemplary embodiments. The structure of the fourth embodiment corresponds essentially to the structure of the second embodiment.

In the fourth embodiment, recording means 26 are also provided for receiving the light reflected from the storage medium 4. The recording means 26 represent an alternative for the eye of the user of the hand-held reading device 2. The recording means 26 are coupled via a beam detector 30 without disturbing the direct beam path for the observing eye. The recording means 26 have an additional magnifying lens 32 and are connected to the display means 14 via a data line 28, so that the real image of the storage medium 4 can be directly displayed and observed by the user.

The representation of the real image of the point distribution of the lithogram is shown in FIG. 6c. You can see the dot distribution of the computer-generated lithogram in the upper left corner as well as a character string in micro script and a logo as a micro image.

Depending on the structure of the third or fourth exemplary embodiment, the images shown in FIGS. 6a and 6b can also be displayed on the display means 14 when the hologram is observed. 7 shows a further embodiment of the present invention. In the exemplary embodiment shown, the hand-held reader 2 is subdivided into an optical block 34 and an evaluation block 36, that is to say of a modular construction.

Inside, the optical block 34 has at least the light source and the receiving means as well as possible further components described above. The evaluation block 36 has at least the evaluation means and the display means 14. The optical block 34 and the evaluation block 36 are connected to one another via an electronic interface 38. The electronic interface has, for example, a ribbon cable and corresponding plug connections on both sides. The standard interfaces for interface cards are possible, for example a Compact Flash card (CF plug-in card). The interface can also be designed optically, for example, as an infrared interface or as a radio interface.

The optical block 34 and the evaluation block 36 are preferably arranged on a common holder (not shown) in order to form the handheld unit and to be easier to handle. One of the two blocks 34 or 36 can have an integrally formed holder, into which the other block can be inserted. The optical block 34 preferably has the holder.

Because it is preferred that the evaluation block 36 is designed as a handheld computer as standard. In combination with the optical block 34, which undergoes less change over time, a combination that can be used in the long term is also created, in which an exchange of the Evaluation unit 36 is possible when the original handheld computer can no longer be procured.

Claims

P A T E N T A N S P R Ü C H E

Reader for reading computer-generated lithograms, which are written in a storage medium (4), with a light source (6) for generating a light beam (8), with recording means (10; 26) for detecting the light beam (8) by illuminating the Lithogram generated image data and with display means (14) for displaying the display data generated from the image data, characterized in that all components are combined in a portable handheld unit.

Reading device according to claim 1, characterized in that the recording means (10; 26) are designed electronically, in particular as a CMOS chip or as a CCD chip.

Reading device according to claim 1 or 2, characterized in that the recording means (10; 26) directly with the

Display means (14) are connected and the

Display means (14) which display image data as display data.

4. Reading device according to one of claims 1 to 3, characterized in that the display means (14) is designed as a conventional display for mobile telephones.

5. Reading device according to one of claims 1 to 4, characterized in that evaluation means (20) are provided for evaluating the image data and for generating the display data.

6. Reading device according to claim 5, characterized in that the evaluation means (20) and the display means (14) are designed as portable handheld computers.

7. Reading device according to claim 5 or 6, characterized in that the display data comprise at least part of the image data, preferably the entire image data.

8. Reading device according to claim 5, characterized in that the display data comprise at least part of the data derived from the image data.

9. Reading device according to one of claims 5 to 8, characterized in that switching means are provided for setting the type of image data.

10. Reading device according to one of claims 1 to 9, characterized in that storage means are provided for storing a plurality of recorded image data.

11. Reading device according to one of claims 1 to 10, characterized in that a magnifying lens (24) is provided as adjusting means.

12. Reading device according to claim 11, characterized in that the magnifying lens (24) is arranged outside or inside the beam path of the light beam (8).

13. Reading device according to claim 11 or 12, characterized in that a light source for illuminating the lithogram, in particular an LED, preferably a white light-generating LED is provided.

14. Reading device according to one of claims 5 to 13, characterized in that the evaluation means (20) analyze the image data continuously recorded by the recording means and hold the image data in a suitable position of the reproduced hologram on the recording means (10).

15. Reading device according to claim 14, characterized in that an acoustic and / or optical signal generator is provided.

16. Reading device according to one of claims 1 to 15, characterized in that the recording means (10) capture the image data of a hologram reproduced by the light beam (8)

17. Reading device according to one of claims 1 to 15, characterized in that the receiving means (26) are provided for receiving the light reflected from the storage medium (4).

18. Reading device according to one of claims 1 to 17, characterized in that at least the light source (6) and the recording means (10) are arranged in an optical block (34), that in an evaluation block (36) at least the evaluation means (20) and the display means (14) are arranged and that the optical block (34) and the evaluation block (36) are connected to one another via an electronic and / or optical interface (38).

19. Reading device according to claim 18, characterized in that the optical block (34) and the evaluation block (36) are arranged on a common holder.

20. Reading device according to claim 18 or 19, characterized in that the evaluation block (36) is designed as a standard handheld computer.